Abstract
In order to examine the relationship between life-history traits and genetic variability, the variation at isozymic loci was investigated in annual and perennial ecotypes at two stages of the life-cycle. Outcrossing rates were also estimatedfrom maternal sibships collected from one annual and two perennial populations. Estimates of 0.04 in the annual, 0.50 and 0.56 in the perennials were obtained based on eight isozyme loci. It was found that: 1) the mating system influenced mainly the level of variation within population; 2) asexual populations and population with a mixed reproductive system differed mainly in their fine-scale intra-population structure; 3) the genetic structure of the annual ecotype depended more on extinction/recolonization events and on their fugitive habit.
